Indurated porous object and process for making same



Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE JOHN J'. KESSLER, OF-ST. I OUIS, MISSOURI.

mnunarnnronous clamor AND rnocnss non MAKING smn No Drawing.

The object of my invention is to produce an indurated orous object by a process which fills the pores of the object with a hard, tough,

non-blistering, water-proofing and electrical insulating organic material; This organic material is a drying and polymerizing oil The method of preparing this oil and the properties of this oil are both described in my U. S. Patent No. 1,616,321 patented Feb By porous objects I mean generally that,

class of materials which contains pores or interstices, and which are therefore more or less absorbent. Examples of porous materials are wood, paper, various fibrous materials, electrical coils, unglazed porcelain, as-

bestos board. These examples are given merely byway of illustration.

Where I use the 'term porous objects throughout this specification and claims, it is'used in thegeneral meaning as including any material or combination of materials which is in whole or in part porous or ab- 0 sorbent.

My improved method of indurating porous objects comprises the use of a general class of indurating material and this general class of indurating material may be briefly described as the drying and polymerizing oil which is formed by the action of bodies containing'a mobile methylene groupupon coal tar fractions boiling between 150 (land 250 C. I

A more detailed description of this drying and polymerizing oil will now be given.

In preparing the polymerizing and dry-' ing oil which is used inthe process which am now describing for indurating porous ob ects,

I start with a fraction of coal tar which has a boiling point range between 150 .C. and

' 250 C. without limiting myself to exactly this boiling range. I treat this coal tar fraction with an amount of formaldehyde 0;; other chemical bodies containing an aldehyde group bodies present,because after the'phenols are Application filed September 24, 1928. Serial No. 308,130.

or of mixtures of chemical bodies which produce by their reaction what is known as an active methylene group.

This is substantially what is involved in the reaction and formaldehyde or other alde- 55 hydes are only two particular ways of utilizing active niethylene groups.

In the preparation of the oil used in this process I start with a coal tar fraction which boils' between approximately 150 and 250 C. This fraction consists of a number of chemical bodies, some of which have been identified, but many of which have not been identified as chemical individuals.

' Among the chemical bodies which may be identified are the phenols or tar acids, naphthalene, coumaf'one and indene. A portionof this oil goes under the name of creo- .sote oil and contains hydrocarbons, saturated and unsaturated together with various compounds of carbon hydrogen and oxygen, traces of compounds ofcarbon hydrogen and nitrogen. Usually such an oil will contain 20% to 50% of phenols'or tar acids. The balance of the oil will consist of'creosote oils which have been partly described as to their chemical character in the foregoing, but which-are as already intimated of more orless indefinite chemical composition.

The properties of the drying and polymerizing oil whichI use in this process do not depend upon the presence of any particular chemical individuals, but they depend upon the presence of the various constituents which are found in the coal tar fraction specified. The polymerizing of the oil depends, for instance, upon the presence of the phenols, but the drying qualities of the oildepend not only upon the phenols, but upon the various other 9O removed from the coal tar fraction, a drying oil can still be'made by my process from the remaining fractions Furthermore, the properties oi? the finished product de end upon the mutually solvent action or t e various constituents of the fraction, which solvent action is mutual whether the oil is in an undried, dried or polymerized condition.

' Whenisucha mixture of oils is subject to the action of formaldehyde or similar substances which may be defined from the standing the last stages of the reaction. Besides this, the reaction products are mutually soluble in each other and in the neutral bodies present in the mixture, so that no separation takes place. A thin film of the finished prod--' uct dries to 'a homogenous transparent film,

consisting of a solid resinous-like mass without gas bubbles and of considerable strength and toughness. In the reaction which I am describing it is worthy of note that the substances present of phenolic character are very much less in proportion than the otheribodies present, butit is a fact that out of such a mixture which is originally oily and liquid a solid product can be produced either by oxidization or by polymerization.

In carrying out my invention I start with a fraction nf-coal tar oil which has a boiling point range between 150 C.'and300 C. without limiting myself to exactly this boiling range. I treat this oil with an amount of formaldehyde or of other aldehyde which is in excess of the amount required to completely polymerize the phenols present. In order to accelerate the reaction, a basic catalyst, such as ammonia or sodium hydrate, may be added to the reacting mixture. I continue the heating until aliquid is obtained of the required viscosity. I find a temperature of about 150 C. to be practical temperature to conduct this heating. In order to illustrate'the change which takes place in the viscosity of the oil on subjecting it to this treatment I will say that a coal tar fraction, such as I have described, will have a viscosity (when measured by a Saybolt instrument at 100 F. of 20-50. After the reaction has proceeded to a practical degree of producing the finished product, the viscosityin the oil has been increased to 200-500 at the same temperature. The oil has, therefore, taken on considerable body and has valuable properties for the induration of porous objects.

Having described the drying and polymerizing oil which I use for indurating porous objects, I will now describe the process or meth 0d of bringing about this induration.

The first ste in the process consists in the saturation of t e porous object with the dr ing and olymerizing oil. This may brought a out by merely dipping the object to be indurated in the oil, or, the saturation may beiacilitated by operating under pressure. I

The degree of saturation or of impregnapure accomplished partly bile methylene group upon tion may be varied b varying the time or pressure used. Any egree of saturation or of'impregnation will depend upon the detailed results to be accomplished.

The second step in the process consists in solidifying and hardening the drying and polymerizing oil used for the saturation or impregnation of the orous object. This is by the removal of the volatile constituents of the oil through evaporation, partlyby the oxidation of the residual solid material and part1 by the polymerization of the residual soli material.

All three processes, evaporation, oxidation,

and polymerization, are hastened bythe effect of heating.

In some cases it is desirable to complete the process while the object to be indurated is bein ressed in a mould in which case it is possi e to prepare an indurated object of uniform dimensions, greater smoothness and greater density.

1am aware that various processes have been described for indurating, moulding, and otherwise fabricating objects which contain phenol aldehyde resins as an indurating material.

Myprocess difiers from processes previously described in two manners, a chemlcal manner and a physical manner. From a chemical standpoint, my process dilfers from rocesses involving the use of phenol alde yde resins in that there are present in my drying and polymerizin beside phenol a dehyde resins, in fact, as shown in my United States Patent No. 1,616,- 321 there are cases in which phenols may be entirely absent from the drying and polymerizing oil described in my United States PatentNo. 1,616,321 and still useful and desirable materials are still obtained. From a physical standpoint I find advantages in the use of a drying and polymerizing oil in which the finished product has the same boiling ran e as the raw material from which it "is ma e. The advantages which I find consist of a uniformity of drying and of polymerization, with a consequent freedom from blisteroil many other substances ing, with a uniform shrinkage, and with a smoothness of finish which are all results due to the fact that the boiling range of the finished product is the same as that of the raw mater1al from which it is made.

I claim: I

1. The process of indurating porous objects which comprises the saturation of the object with a drying and polymerizing oil prepared b the action of chemical bodies having a motar fractions having a boihng range between 150 C. and 250 C.

2. The process of indurating porous objects which comprises the saturation of the object with a drying and polymerizing oil repared by the action of chemical bo ies aving a r eeogees mobile methylene group upon tor fractions leaving a boiling range between 150 C end 250C. and finally the baking of the object. 3. The process ofinclureting porous obi ects which comprises the saturation of the object with adrying and polymerizing oil pregoerei by the action of chemicel bodies having a mo bilemethylene group upon coal tar fractions having a boiling range between 150 C. one 250 m 4. The process of indureting porous objects which comprises the'saturetion of the object with a, drying SLDd' polymerizing oii preperefl by the action otforrnaldehyc'ie upon tar frections having is boiling range between 150 6.

and 250. (1,

, 5. The process "of imiureting porous objects which comprises the saturation of the object with e drying and polymerizing oil prepared 29 by the action of formaldehyde with the semition out o catalyst upon tar fractions having a toiling range of 150 C, and 250 C.

B. The process of insulating magnet Wire which comprises the saturation of the porous covering of the wire with e drying and polymerizing oil prepared. by the action of chemice]. bodies having a mobileimethylene group upon terrfrsctions having a boiling range of 150 (O2 to 250 C. oi} '7. The process of insuleting magnet Wire which comprises the saturation of the po ro is covering of the wire with on insulating compound containing a drying and polymeroil prepared 10 the action of chemicsi bodies having a. mobile methylene group upon tor fractions hovinge boiling range of 150 Co to 250 "C; k

8. As an article of manufacture s porous object which has been imiurtited; with e 6m ing and polymerizing oil preperefi by the action of chemical bodies having a, mobile methylene group upon tar fractions having e lioiling'renge of 150 C. to 250 C.

In testimony that I claim the foregoing I re hereunto o my signature.

JOHN J.- KESSLER. 

